This invention relates generally to compressors for refrigeration, air conditioners, or heat pumps, and is more particularly concerned with a vibration-isolating mounting assembly for mounting the compressor to its associated base pan.
It is customary in the design of air conditioning systems to mount the refrigerant compressor to the base pan of the condensing or outdoor unit. In such an installation, it is desirable to silence the unit by damping vibrations caused by operation of the compressor. This can be accomplished by positioning elastomeric grommets between the base or feet of the compressor and the base pan on which it is mounted. The grommets are attached to the compressor feet and the compressor, with grommets, is set on the base pan. Threaded studs (with sleeves) are then pushed through the grommets and screwed into mounting holes in the base pan.
A recent improvement on this conventional mounting assembly is described in commonly-assigned U.S. Pat. No. 5,221,192, incorporated by reference herein. That approach recognizes that a rigid stud can transmit vibrations from the compressor to the base pan. This approach eliminates the "through bolt" structure of the conventional stud mount, instead employing a "sandwich" elastomeric isolator arrangement where upper and lower threaded steel stud sections are joined by an elastomeric middle section. This arrangement isolates vibration much better than the conventional stud and grommet technique, and also has a greater tolerance for lateral movement of the compressor, which transfers vibrational energy into heat energy.
However, the mounting arrangement, with the compressor mounted on these elastomeric isolators directly onto the base pan, still transmits more vibration to the base pan than is desirable, and it is likewise desired to reduce the sound levels associated with the outdoor unit. On the other hand, the mounting arrangement must still be rugged enough to withstand transit and to ensure trouble-free usage after installation.